package com.example.forum.intercepetor;

import com.example.forum.config.AppConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * @Author: wenjingyuan
 * @Date: 2023/09/24/16:58
 * @Description:用户登录拦截器
 */
@Component
public class LoginInterceptor implements HandlerInterceptor {
    @Value("${bit-forum.login.url}")
    private String defaultUrl;
    /**
     * 请求的前置处理
     * @param request
     * @param response
     * @param handler
     * @return true就继续流程 <br/> false 流程中断
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //获取session对象
        HttpSession session = request.getSession(false);
        //判断session是否有效
        if(session!=null && session.getAttribute(AppConfig.USER_SESSION)!=null){
            //用户已登录，校验成功
            return true;
        }
        //首先我们需要检查url是否正确
        if(!defaultUrl.startsWith("/")){
            defaultUrl="/"+defaultUrl;
        }
        //校验失败，跳转到登录页
        response.sendRedirect(defaultUrl);
        //中断流程
        return false;
    }
}
